Let's assume that you have a system with the usual feedback configuration as shown below.

Here is the Bode' plot for G(s).  (And, yes, it is a Bdoe' plot for a system you can build.

• Determine the best SSE (step input) that can be achieved.
• Determine the best SSE (step input) that can be achieved with a 40^o phase margin.
• Evaluate this system - whether it is easy or difficult to control and get good performance.  Good performance would be small SSE with stability.